美国能源部劳伦斯伯克利国家实验室和加州大学的研究人员利用一种全新的光激活蛋白和基因表达技术,观察到斑马鱼幼虫尾鳍控制游动的一种神经细胞。这项研究发表在9月17日Nature杂志上。
该研究利用了一种几年前开发出来的光激活蛋白,可以通过基因工程的手段使该蛋白的基因在神经元或其他细胞中表达,并起到光学开关的作用。为了测试这种光激活开关,研究人员利用该蛋白寻找控制斑马鱼幼虫神经回路中的神经细胞。
首先,研究人员利用几百条斑马鱼的基因组随机地表达光激活蛋白,发现在肌肉细胞,骨细胞或中枢神经细胞有光激活蛋白表达。接着研究人员选择那些在脊髓神经细胞中表达光激活蛋白的斑马鱼——已知这些神经细胞控制斑马鱼的运动。
然后,研究人员在用光源照射斑马鱼幼虫,发现这些斑马鱼同时摆动尾鳍开始游动。进一步分析表明,这些斑马鱼的一种名为Kolmer-Agduhr的神经元中光激活蛋白都得以表达。(生物谷Bioon.com)
生物谷推荐原始出处:
Nature 461, 407-410 (17 September 2009) | doi:10.1038/nature08323
Optogenetic dissection of a behavioural module in the vertebrate spinal cord
Claire Wyart1,5, Filippo Del Bene2,5, Erica Warp1, Ethan K. Scott2,6, Dirk Trauner3, Herwig Baier2 & Ehud Y. Isacoff1,4
1 Helen Wills Neuroscience Institute and Department of Molecular and Cell Biology, University of California in Berkeley, Berkeley, California 94720, USA
2 Department of Physiology, Program in Neuroscience, University of California in San Francisco, San Francisco, California 94158-2324, USA
3 Department of Chemistry, Ludwig Maximilians-Universit?t, Munich, Germany
4 Physical Bioscience Division and Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
5 These authors contributed equally to this work.
6 Present address: School of Biomedical Sciences, University of Queensland, Queensland 4072, Australia.
Locomotion relies on neural networks called central pattern generators (CPGs) that generate periodic motor commands for rhythmic movements1. In vertebrates, the excitatory synaptic drive for inducing the spinal CPG can originate from either supraspinal glutamatergic inputs or from within the spinal cord2, 3. Here we identify a spinal input to the CPG that drives spontaneous locomotion using a combination of intersectional gene expression and optogenetics4 in zebrafish larvae. The photo-stimulation of one specific cell type was sufficient to induce a symmetrical tail beating sequence that mimics spontaneous slow forward swimming. This neuron is the Kolmer–Agduhr cell5, which extends cilia into the central cerebrospinal-fluid-containing canal of the spinal cord and has an ipsilateral ascending axon that terminates in a series of consecutive segments6. Genetically silencing Kolmer–Agduhr cells reduced the frequency of spontaneous free swimming, indicating that activity of Kolmer–Agduhr cells provides necessary tone for spontaneous forward swimming. Kolmer–Agduhr cells have been known for over 75 years, but their function has been mysterious. Our results reveal that during early development in zebrafish these cells provide a positive drive to the spinal CPG for spontaneous locomotion.